Abstract

Seawater desalination is now commonly performed using membrane technology; however, membrane biofouling is considered a critical issue affecting desalination plants. The incorporation of inorganic particles with antimicrobial properties into reverses osmosis (RO) membranes has been reported as an effective route for enhancing the antibiofouling properties but it could diminishing the performance of desalination. The aim of this work was to study the desalinization performance of antibiofouling RO membranes by incorporating antimicrobial nanoparticles like copper oxide (CuO). These nanoparticles were entrapped within of the structure of membrane during the interfacial polymerization process. The membranes were characterized by field-emission scanning electron microscopy (FESEM), energy-dispersive X-ray spectroscope (EDX) and atomic force microscopy (AFM) in order to observe the morphologies of the membranes and verify the incorporation of nanoparticles within them. Bactericidal tests were performed using Escherichia coli and anti-adhesion on the membranes was confirmed using epifluorescence microscopy. The performance of the membrane was evaluated in terms of permeate flux and salt rejection by using a cross flow test cell with an effective area of 36 cm2 and a feed solution of 1000 ppm NaCl at 300psi. FESEM and EDX analyses confirmed that the nanoparticles were embedded into the membrane and AFM images showed that the modified membranes exhibited a lower surface roughness which favors the bacterial anti-adhesion. These membranes showed an excellent anti-bacterial and anti-adhesion effect arising from the decrease in its surface roughnesses and bactericidal nature of the Cu2+ ions released from the membrane. The desalination performance of modified membranes showed an important salt rejection of about 95% with stable water flux about 30 L.m−2.h−1 and a recovery of 50%. Also a negligible loss of copper in the permeate water was observed. In conclusion, the incorporation of CuO nanoparticles into RO membranes improves the antibiofouling capacities without diminishing the performance of desalination.